One-dimensional organic nanowires provide a valuable platform for understanding the emergent electronic phenomena in organic semiconductor materials. We have prepared a class of organic nanowires consisting of stacked pi-conjugated building blocks covalently attached to a solubilizing backbone. We have formed self-assembled monolayers from nanowires of various lengths and sequence contexts on gold substrates and characterized their properties with a range of techniques, including x-ray photoelectron spectroscopy (XPS), near-edge x-ray absorption fine structure spectroscopy (NEXAFS), and resonant photoemission spectroscopy (RPES). These studies have elucidated the nanowires’ electronic structure and charge carrier dynamics, geometric orientation at solid substrates, and interaction with the surrounding environment. Our experiments may offer improved insight into the design of pi-conjugated materials for organic electronic applications.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 2797156We have investigated bidirectional femtosecond charge transfer dynamics using the core–hole clock implementation of resonant photoemission spectroscopy from 4,4'-bipyridine molecular layers on different surfaces: Au(111) and epitaxial graphene on Ni(111). We showed that the lowest unoccupied molecular orbital (LUMO) of the molecule drops partially below the Fermi level upon core–hole creation in all systems, opening an additional decay channel for the core–hole, involving electron donation from substrate to the molecule. Using the core–hole clock method, we find that the bidirectional charge transfer time between the substrate and the molecule is 2 fs on Au(111), and around 4 fs for epitaxial graphene.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 2789988